Oil and gas industry gooseneck manufactured by hot isostatic pressing and a flexible pipeline assembly with an oil and gas industry gooseneck

ABSTRACT

The present invention relates to an oil and gas industry gooseneck with a fluid duct portion with at least an arch shaped portion, a first connecting portion, a second connecting portion a lifting pad eye and a shackle interface along the arch shaped fluid duct portion. The gooseneck is one Hot Isostatic Pressed element. An oil and gas industry flexible pipeline assembly with a hipped gooseneck is also disclosed.

TECHNICAL FIELD

The present invention relates to a one-piece gooseneck manufactured by Hot Isostatic Pressing (HIP).

The present invention focuses on manufacturing a one-piece product of gooseneck for use in industry related to the production of oil and gas in duplex or super duplex utilizing a HIP (hot isostatic pressing) process. HIP provides a near net shape product with superior and uniform material properties. In addition, the design utilizes an integrated pad-eye with a shackle interface that eliminates the need for a costly lifting adapter. Lifting adapters have load limitations related to up-bending of an end of a flexible pipeline. This limitation is removed when using a shackle interface. The gooseneck of the invention is engineered as one piece using flexible engineering and requires less time from a finished design phase to a finished product. Only minor machining is required to finish the gooseneck.

BACKGROUND

An oil and gas industry gooseneck is a U-shaped terminal fitting designed for carrying the weight and pressure of a several kilometers long pipeline, typically with one end attached to a FPSO (floating production storage and offloading) or other production platforms used in the oil and gas industry. The gooseneck is attached to the end of a flexible pipeline that is lifted and lowered to be connected to a hosting structure subsea. The term “gooseneck” is used in various technical fields, but the present invention defines an oil and gas industry gooseneck to limit the invention to goosenecks of the above type.

Traditional goosenecks are manufactured as traditional welded designs with a pipe section that requires numerous process steps and internal piping that carry the internal pressure, held in a lifting frame that carry external loads (in place and lifting). Longitudinal welds along pipes are not acceptable according to relevant industry standards, making welded structures more complicated. Welded designs thus require numerous manufacturing processes. Welded designs rely on a forged hub and an end fitting that requires machining, cladding, and then machining of the lifting element to a final shape before the lifting element is welded onto the pipe section. The piping requires induction bending, before being welded to the end fittings.

Oil and gas industry gooseneck assemblies are normally used as part of the termination of risers, i.e. the connection between a floating production, storage and offloading (FPSO) (topside) and to a pipeline end termination (PLET) (subsea).

Goosenecks are designed to lift and terminate the flexible pipe to a subsea host structure, e.g. to a PLET or a well jumper, e.g. between a valve-tree and a manifold. Both the valve-tree and the manifold include a hosting structures to allow connection of a gooseneck. A flexible pipeline assembly has a gooseneck at each end that is connected to the hosting structure at the valve tree and the manifold respectively.

In in relation to the present invention is super duplex intended to describe stainless steels, typically grade EN 1.4410 developed to meet specific demands of the oil& gas and the chemical industries. They offer the required corrosion resistance and strength. Super duplex stainless steels are difficult to process due to high contents of Cr, Ni, Mo, N and W. A duplex stainless steel may also be used.

SUMMARY

Using the hot isostatic pressing- or “Hipping” process allows the gooseneck of the invention to be tailor-made without welding and the gooseneck will thus not include weaknesses or cracks due to welding. During hot isostatic pressing, fine metal powder is provided in a capsule/casting. The capsule is heated to an elevated temperature and isostatic gas pressure is applied. The resulting gooseneck is a solid and dense unit with no inclusions. Not only does this offer more design freedom than traditional assembly, forging or casting, it also reduces the risk of hydrogen induced stress cracking (HISC) due to the very fine microstructure of the finished gooseneck. Time-consuming welding and inspections in the forging-machining process is eliminated, lead times and costs can be reduced and up-or down scaling is simple.

The present invention thus results in simplified and flexible engineering, i.e. one finished piece, reduced delivery schedule, and a minimum of assembly.

The simplified gooseneck design reduces costs and makes alterations simple.

The present invention thus concerns an oil and gas industry gooseneck comprising a fluid duct portion with at least an arch shaped portion, a first connecting portion, a second connecting portion, a lifting pad eye with a shackle interface lifting pad eye extending along the arch shaped fluid duct portion. The gooseneck is one hot isostatic pressed element.

The gooseneck may be made of a Duplex or a Super-duplex material.

The lifting pad eye may extend along a convex part of the fluid duct portion.

The lifting pad eye may be plate shaped.

Furthermore, the present invention relates to an oil and gas industry flexible pipeline assembly with an oil and gas industry gooseneck as described above, and a flexible pipeline connected to the second connecting portion and onto a subsea host structure.

The oil and gas industry flexible pipeline assembly may further include a guiding structure with a clamp connector connected to the first connecting portion.

The guiding structure with a clamp connector may be adapted to be connected to a guiding structure with a female hub assembled to a subsea structure.

The invention also relates to use of hot isostatic pressing to manufacture an oil and gas industry gooseneck as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 , is a perspective view of a one piece, hipped, gooseneck of the invention;

FIG. 2 , is a side view of an oil and gas industry flexible pipeline assembly of the invention with a gooseneck connected to a flexible pipeline; and

FIG. 3 is a perspective view of the hipped, gooseneck of the invention attached to a guiding structure with a clamp connector.

DETAILED DESCRIPTION

FIG. 1 , shows a one-piece, hipped gooseneck 1 with a fluid duct portion 5 and an integrated lifting pad eye 3 formed with an integrated lifting shackle interface 4 according to the invention. The shackle interface 4 includes a shackle opening and a width adapted to a shackle internal width. The shackle opening is a bore with a diameter adapted to a diameter of a shackle pin. The fluid duct portion is curved. The lifting pad eye 3 extends along the convex outer portion of the curved fluid duct portion 5. The gooseneck 1 is typically assembled to a guiding structure and a connector. The gooseneck 1 has a first connecting portion 6 with a male hub for attachment of a metal seal to allow full pressure and structural integrity once connected to a subsea hosting structure. The hosting structure has a guiding structure and a female hub to allow the full connection. The hosting structure may form a part of a subsea structure, such as a valve tree, a manifold, a PLET (pipeline end termination) or for a topside floating production storage and offloading (FPSO) that is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil. The gooseneck 1 is typically attached through the second connecting portion 2 to a flexible pipeline with or without a swivel. The purpose of the swivel is to remove torsional loads induced in the flexible pipeline. The lifting pad eye 3 with the shackle interface 4 is integrated in the gooseneck 1. The integrated lifting pad eye 3 distributes the stresses when the integrated lifting shackle interface 4 is used to lift the gooseneck 1. The integrated lifting interface forming the lifting padeye is provided for attachment of the lifting shackle to the gooseneck 1. The shape of the integrated lifting interface conforms to the outer shape of the fluid duct portion 5. A curved centreline along the duct portion 5 defines a plane and the lifting pad eye 3 is located symmetrically in this plane. The base connecting portion 6 and the second connecting portion 2 forming a hose connecting portion may be hub connecting portions and may include threads or flanges, typically API flanges. The connecting portion 6 may be a male hub to allow for installation of a metal seal. The gooseneck 1 may form a part of a VCCS (vertical clamp connection system).

FIG. 2 shows a flexible pipeline assembly with the gooseneck 1 connected to a flexible pipeline 7 with a bending limiting element. The flexible pipeline 7 includes a pipeline first end 8 connected to the second connecting portion 2 and a pipeline second end 9 connected onto a subsea host structure 18. The subsea host structure 18 may include a second gooseneck (not shown), and the pipeline second end 9 may be connected to this gooseneck to form a connection between the subsea host structure 18 and the pipeline 7 second end 9. The subsea host structure 18 and topside host structure will then be connected, i.e the first end of the second gooseneck will be connected to the subsea host structure 18. A guiding structure with a clamp connector 10 is connected to the first connecting portion 6 of the gooseneck 1. The guiding structure with a clamp connector 10 is adapted to be connected to a guiding structure with a female hub 11 assembled to a subsea structure. The flexible pipeline 7 is typically on a reel before it is installed. A separate pad eye 12 on the convex part of the gooseneck 1 may be provided for onshore handling.

FIG. 3 shows a gooseneck assembly with the gooseneck 1, a clamp connector with a torque tool bucket 17, a back-seal test port receptacle 13 for a back-seal test port, and an insulation plug lock bolt 16 on a downfacing assembly 15 of a vertical clamp connection system. The second connecting portion 2 is shown with an API flange on the gooseneck 1 with the shackle interface 4, the base connecting portion 6 and the separate pad eye 12 for onshore handling. 

1. An oil and gas industry gooseneck comprising a fluid duct portion with at least an arch shaped portion, a first connecting portion, a second connecting portion, a lifting pad eye with a shackle interface extending along the arch shaped fluid duct portion, and wherein the gooseneck is one hot isostatic pressed element.
 2. The gooseneck of claim 1, wherein the gooseneck is made of a Super-duplex material.
 3. The oil and gas industry goose neck of claim 1 wherein the lifting pad eye extends along a convex part of the fluid duct portion.
 4. The oil and gas industry goose neck of claim 1 wherein the lifting pad eye is plate shaped.
 5. An oil and gas industry flexible pipeline assembly comprising an oil and gas industry gooseneck of claim 1, and a flexible pipeline with a first end connected to the second connecting portion and a second end connected onto a subsea host structure.
 6. The oil and gas industry flexible pipeline assembly of claim 5, further including a guiding structure with a clamp connector connected to the first connecting portion.
 7. The oil and gas industry flexible pipeline assembly of claim 6, wherein the guiding structure with a clamp connector is adapted to be connected to a guiding structure with a female hub assembled to a subsea structure.
 8. Use of hot isostatic pressing to manufacture an oil and gas industry gooseneck of claim
 1. 